A data link control protocol for low earth orbit satellite networks has been developed to overcome throughput limitations inherent in event-based positive acknowledgment automatic-repeat-request class protocols. This was accomplished by relaxing a reliability constraint, specifically, the in-sequence delivery constraint. This relaxation results in a new class of link layer service, that of reliable datagram, and permits a fresh approach to link layer protocol design. In this paper we present one such protocol, the low altitude multiple satellite data link control (LAMS-DLC) protocol. We derive the throughput efficiency of LAMS-DLC and compare the results with HDLC (selective reject). The analysis is verified using an event-based simulation. Measurements suggest that LAMS-DLC provides near optimal throughput efficiencies in the target environment, while using significantly less buffer space than that required for HDLC-SREJ.

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This paper discusses design considerations for a gigaspeed data link control(DLC) protocol designed for low altitude multiple satellite(LAMS) networks. Two important and intimately interrelated design issues are reliability and performance. Both of these are influenced by the inconsistency gap(1,) associated with the protocol. Closely associated measures are bounded maximum sender queueing time(MSQT) and maximum receiver holding time(MRHT). This paper discusses these time measures. In LAMS-DLC both MSQT and MRHT are bounded, thus I, is also bounded. With I, bounded LAMS-DLC permits continuous operation(i.e. if the DLCP has data available for transmission it will be sent without protocol delays) provided the link is active. These benefits are obtained by relaxing the FIFO reliability constraint found in conventional DLC protocols without permitting packet loss or duplication.

In this paper we introduce a new data link control protocol appropriate for a low earth orbit (LEO) satellite network.The principal characteristics of an LEO satellite network are high error rat es, long propagation delay, and high mo--

LAMS‐DLC, a data link control protocol for low altitude satellite networks, was developed to overcome throughput limitations inherent in event‐based positive acknowledgment (POS‐ACK) automatic repeat request (ARQ) class protocols by relaxing certain reliability constraints, in particular the in‐sequence delivery constraint. This relaxation results in a new class of link layer service, that of reliable datagram, and permits a fresh approach to link layer protocol design. In this paper we discuss the motivation for such a protocol, describe one such protocol, LAMS‐DLC, and compare throughput efficiency with results obtained from a simulation model. Results suggest that LAMS‐DLC provides near optimal throughput efficiencies in the target environment, while using significantly less buffer space than is required for conventional POS‐ACK protocols.